| 1 | /* Function for handling the GLib event loop. |
| 2 | |
| 3 | Copyright (C) 2009-2013 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GNU Emacs. |
| 6 | |
| 7 | GNU Emacs is free software: you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation, either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | GNU Emacs is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <config.h> |
| 21 | |
| 22 | #include "xgselect.h" |
| 23 | |
| 24 | #ifdef HAVE_GLIB |
| 25 | |
| 26 | #include <glib.h> |
| 27 | #include <errno.h> |
| 28 | #include <timespec.h> |
| 29 | #include "frame.h" |
| 30 | |
| 31 | int |
| 32 | xg_select (int fds_lim, fd_set *rfds, fd_set *wfds, fd_set *efds, |
| 33 | struct timespec const *timeout, sigset_t const *sigmask) |
| 34 | { |
| 35 | fd_set all_rfds, all_wfds; |
| 36 | struct timespec tmo; |
| 37 | struct timespec const *tmop = timeout; |
| 38 | |
| 39 | GMainContext *context; |
| 40 | int have_wfds = wfds != NULL; |
| 41 | GPollFD gfds_buf[128]; |
| 42 | GPollFD *gfds = gfds_buf; |
| 43 | int gfds_size = sizeof gfds_buf / sizeof *gfds_buf; |
| 44 | int n_gfds, retval = 0, our_fds = 0, max_fds = fds_lim - 1; |
| 45 | int i, nfds, tmo_in_millisec; |
| 46 | USE_SAFE_ALLOCA; |
| 47 | |
| 48 | /* Do not try to optimize with an initial check with g_main_context_pending |
| 49 | and a call to pselect if it returns false. If Gdk has a timeout for 0.01 |
| 50 | second, and Emacs has a timeout for 1 second, g_main_context_pending will |
| 51 | return false, but the timeout will be 1 second, thus missing the gdk |
| 52 | timeout with a lot. */ |
| 53 | |
| 54 | context = g_main_context_default (); |
| 55 | |
| 56 | if (rfds) all_rfds = *rfds; |
| 57 | else FD_ZERO (&all_rfds); |
| 58 | if (wfds) all_wfds = *wfds; |
| 59 | else FD_ZERO (&all_wfds); |
| 60 | |
| 61 | n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec, |
| 62 | gfds, gfds_size); |
| 63 | if (gfds_size < n_gfds) |
| 64 | { |
| 65 | SAFE_NALLOCA (gfds, sizeof *gfds, n_gfds); |
| 66 | gfds_size = n_gfds; |
| 67 | n_gfds = g_main_context_query (context, G_PRIORITY_LOW, &tmo_in_millisec, |
| 68 | gfds, gfds_size); |
| 69 | } |
| 70 | |
| 71 | for (i = 0; i < n_gfds; ++i) |
| 72 | { |
| 73 | if (gfds[i].events & G_IO_IN) |
| 74 | { |
| 75 | FD_SET (gfds[i].fd, &all_rfds); |
| 76 | if (gfds[i].fd > max_fds) max_fds = gfds[i].fd; |
| 77 | } |
| 78 | if (gfds[i].events & G_IO_OUT) |
| 79 | { |
| 80 | FD_SET (gfds[i].fd, &all_wfds); |
| 81 | if (gfds[i].fd > max_fds) max_fds = gfds[i].fd; |
| 82 | have_wfds = 1; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | SAFE_FREE (); |
| 87 | |
| 88 | if (tmo_in_millisec >= 0) |
| 89 | { |
| 90 | tmo = make_timespec (tmo_in_millisec / 1000, |
| 91 | 1000 * 1000 * (tmo_in_millisec % 1000)); |
| 92 | if (!timeout || timespec_cmp (tmo, *timeout) < 0) |
| 93 | tmop = &tmo; |
| 94 | } |
| 95 | |
| 96 | fds_lim = max_fds + 1; |
| 97 | nfds = pselect (fds_lim, &all_rfds, have_wfds ? &all_wfds : NULL, |
| 98 | efds, tmop, sigmask); |
| 99 | |
| 100 | if (nfds < 0) |
| 101 | retval = nfds; |
| 102 | else if (nfds > 0) |
| 103 | { |
| 104 | for (i = 0; i < fds_lim; ++i) |
| 105 | { |
| 106 | if (FD_ISSET (i, &all_rfds)) |
| 107 | { |
| 108 | if (rfds && FD_ISSET (i, rfds)) ++retval; |
| 109 | else ++our_fds; |
| 110 | } |
| 111 | else if (rfds) |
| 112 | FD_CLR (i, rfds); |
| 113 | |
| 114 | if (have_wfds && FD_ISSET (i, &all_wfds)) |
| 115 | { |
| 116 | if (wfds && FD_ISSET (i, wfds)) ++retval; |
| 117 | else ++our_fds; |
| 118 | } |
| 119 | else if (wfds) |
| 120 | FD_CLR (i, wfds); |
| 121 | |
| 122 | if (efds && FD_ISSET (i, efds)) |
| 123 | ++retval; |
| 124 | } |
| 125 | } |
| 126 | |
| 127 | if (our_fds > 0 || (nfds == 0 && tmop == &tmo)) |
| 128 | { |
| 129 | |
| 130 | /* If Gtk+ is in use eventually gtk_main_iteration will be called, |
| 131 | unless retval is zero. */ |
| 132 | #ifdef USE_GTK |
| 133 | if (retval == 0) |
| 134 | #endif |
| 135 | while (g_main_context_pending (context)) |
| 136 | g_main_context_dispatch (context); |
| 137 | |
| 138 | /* To not have to recalculate timeout, return like this. */ |
| 139 | if (retval == 0) |
| 140 | { |
| 141 | retval = -1; |
| 142 | errno = EINTR; |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | return retval; |
| 147 | } |
| 148 | #endif /* HAVE_GLIB */ |